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Pulmonary artery
| Caption = Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow. (Pulmonary artery labeled at upper right.) | BranchFrom = right ventricle | BranchTo = | System = Cardiovascular, Respiratory | Precursor = truncus arteriosus | Supplies = | MeshName = Pulmonary+Artery | MeshNumber = A07.231.114.715 | DorlandsPre = t_20 | DorlandsSuf = 12826098 }} The pulmonary artery carries deoxygenated blood from the heart to the lungs. It is one of the only arteries (other than the umbilical arteries in the fetus) that carry deoxygenated blood. Structure In the human heart, the pulmonary trunk' (pulmonary artery or main pulmonary artery) begins at the base of the right ventricle. It is short and wide—approximately in length and in diameter. It then branches into two pulmonary arteries (left and right), which deliver deoxygenated blood to the corresponding lung. Embryology Function The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. The blood here passes through capillaries adjacent to alveoli and becomes oxygenated as part of the process of respiration. In contrast to the pulmonary arteries, the bronchial arteries supply nutrition to the lungs themselves. Pulmonary artery pressure The pulmonary artery pressure is a measure of the blood pressure found in the pulmonary artery. This is measured by inserting a catheter into the pulmonary artery. The mean pressure is typically 9 - 18 mmHg.,Edwards Lifesciences LLC > Normal Hemodynamic Parameters – Adult 2009 and the wedge pressure measured in the left atrium may be 6-12mmHg. The wedge pressure may be elevated in left heart failure and other conditions, such as sickle cell disease. Clinical significance The pulmonary artery is relevant in a number of clinical states. Pulmonary hypertension is used to describe an increase in the pressure of the pulmonary artery, and may be defined as a mean pulmonary artery pressure of greater than 25mmHg. This may occur as a result of heart problems such as heart failure, lung or airway disease such as COPD or scleroderma, or thromboembolic disease such as pulmonary embolism or emboli seen in sickle cell anaemia. Pulmonary embolism refers to an emboli that lodges in the pulmonary circulation. This may arise from a deep venous thrombosis, especially after a period of immobility. A pulmonary embolus is a common cause of death in patients with cancer and stroke. A large pulmonary embolus affecting the pulmonary trunk is called a saddle embolus. Additional images File:Relations of the aorta, trachea, esophagus and other heart structures.png|Image showing main pulmonary artery coursing ventrally to the aortic root and trachea, and the right pulmonary artery passes dorsally to the ascending aorta, while the left pulmonary artery passes ventrally to the descending aorta. Image:Illu bronchi lungs.jpg|Bronchi, bronchial tree, and lungs Image:Illu pulmonary circuit.jpg|Pulmonary circuit Image:Gray503.png|Transverse section of thorax, showing relations of pulmonary artery. Image:Gray1032.png|The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.Crystal. See also * Chronic obstructive lung disease * Pulmonary hypertension * Thromboembolic disease * Pulmonary circulation * Rasmussen's aneurysm External links * * * - "Heart: The Pericardial sac and Great vessels" * - "Heart: Openings of Great Vessels into the Pericardial Sac" * - "Mediastinal surface of the right lung." * - "Mediastinal surface of the left lung." * References Category:Arteries of the thorax